#IFNDEF __lib_joystick
#DEFINE __lib_joystick 1

GOTO __skip_lib_joystick

// ============================================================================
// JOYSTICK INPUT DRIVER FOR COMMODORE 64
// ============================================================================
// This library provides joystick input reading for the Commodore 64.
//
// Joystick reading uses CIA port 2 ($DC00) which is preferred for games
// Port 1 ($DC01) conflicts with keyboard matrix scanning
//
// Usage:
//   #INCLUDE "joystick.c65"
//   WHILE 1
//     joy_read()
//     BYTE test_bit
//     test_bit = joy_state & JOY_UP_MASK
//     IF test_bit
//       // handle up
//     ENDIF
//   WEND
// ============================================================================

// CIA Port addresses
WORD CONST JOY_PORT1 = $DC01  // Port 1 (conflicts with keyboard)
WORD CONST JOY_PORT2 = $DC00  // Port 2 (recommended for games)

// Joystick bit masks (active low - 0 = pressed)
BYTE CONST JOY_UP_MASK = %00000001      // Bit 0
BYTE CONST JOY_DOWN_MASK = %00000010    // Bit 1
BYTE CONST JOY_LEFT_MASK = %00000100    // Bit 2
BYTE CONST JOY_RIGHT_MASK = %00001000   // Bit 3
BYTE CONST JOY_FIRE_MASK = %00010000    // Bit 4

// Joystick state variable
BYTE joy_state        // Inverted joystick state (1=pressed, 0=not pressed)



// ============================================================================
// FUNC joy_read_port1
// Read joystick port 1 (alternative port, may conflict with keyboard)
// Updates the same joy_state variable as joy_read()
// ============================================================================
FUNC joy_read_port1
  BYTE joy_raw

  joy_raw = PEEK JOY_PORT1
  joy_state = joy_raw ^ $FF  // Invert bits: 1=pressed, 0=not pressed
FEND

// ============================================================================
// FUNC joy_read
// Read joystick port 2 and update state variable
// Call this every frame to update joystick state
// Inverts active-low CIA bits to active-high (1=pressed, 0=not pressed)
// ============================================================================
FUNC joy_read_port2
  BYTE joy_raw

  joy_raw = PEEK JOY_PORT2
  joy_state = joy_raw ^ $FF  // Invert bits: 1=pressed, 0=not pressed
FEND



LABEL __skip_lib_joystick

#IFEND